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MIC2145
Micrel, Inc.
MIC2145
High Efficiency 2.5W Boost Converter
General Description
Features
The MIC2145 is a small size boost switching regulator that can provide over 2.5W of output power. The input voltage range is between 2.4V to 16V, making the device suitable for one-cell Li-Ion and 3- to 4-cell alkaline/NiCad/NiMH applications. The output voltage of the MIC2145 can be adjusted up to 16V.
The MIC2145 is well suited for portable, space-sensitive applications. Its typical 450kHz operation allows small surface mount external components to be used. The MIC2145 has a low quiescent current of 200µA, and a typical shutdown current of 0.5µA. The MIC2145 is capable of high efficiencies in a small board area.
The MIC2145 features a low-on resistance internal switch that allows it to provide over 2.5W of output power. The peak switch current can be programmed through an external resistor. This allows the user to set the peak switch current at the level where maximum efficiency occurs. It also allows the user to further optimize for efficiency and inductor size by setting the peak current below the level of inductor saturation.
• 2.4V to 16V input voltage • Output adjustable to 16V • Programmable peak current limit • Soft start • Up to 450kHz switching frequency • 0.5µA shutdown current • 200µA quiescent current • Capable of 5V/ 500mA output with 3.3V input • Achieves over 85% efficiency • Implements low power BOOST, SEPIC, and FLYBACK
topologies • MSOP-8 and 3mm×3mm MLF™-10L
Applications
• Flash LED driver • LCD bias supply • White LED driver • DSL bias supply • Local 3V to 5V conversion
The MIC2145 is available in an MSOP-8 and 3mm×3mm MLF™-10L package with an ambient operating temperature
range from –40°C to +85°C.
Ordering Information
Part Number
Standard
Pb-Free
MIC2145BMM MIC2145YMM
MIC2145BML MIC2145YML
Voltage
Adj Adj
Ambient Temp. Range
–40°C to +85°C –40°C to +85°C
Package 8-lead MSOP 10-lead MLF™
Typical Application
VIN 3.0V to 5.0V
CIN 10µF/6.3V
I Limit
L1 10µH
1
EN
5
SW
4
PGND
6
VDD
MIC2145BMM
3
RSET
FB 7
D1
2 SS
SGND 8
VOUT 10V/150mA
COUT 10µF/16V
EFFICIENCY (%)
10V Output Efficiency
90
85
80
75
70
65 VIN = 3.0V
6010 100 1000 OUTPUT CURRENT (mA)
Adjustable Output Boost Converter with Programmable Peak Switch Current
MLF and MicroLeadFrame are trademarks of Amkor Technologies, Inc.
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
April 2005
1 M9999-042205
MIC2145
Pin Configuration
EN 1 SS 2 RSET 3 PGND 4
8 SGND 7 FB 6 VDD 5 SW
8-Lead MSOP (MM)
Micrel, Inc.
EN SS RSET PGND PGND
1 2 3 4 5
10 SGND 9 FB 8 VDD 7 SW 6 SW
3mm×3mm MLF-10L (ML)
Pin Description
Pin Number MSOP
1
Pin Number MLF
1
22
33
4 4, 5 5 6, 7 68 79 8 10
Pin Name
EN
SS
RSET
PGND SW VDD FB
SGND
Pin Function
Enable (Input): Logic high (≥1.5V) enables regulator. Logic low (≤0.7V) shuts down regulator. Do not float. Soft Start Capacitor (Extern.